Insulation stripping attachment for electrical connector crimping press and connector crimping press having insulation stripping means

ABSTRACT

A STRIPPER ATTACHMENT FOR A CRIMPING PRESS COMPRISING WIRE GRIPPING JAWS AND AN INSULATION STRIPPING DEVICE. THE JAWS ARE MOUNTED ON A JAW-OPERATING CYLINDER WHICH SWINGS ABOUT A PIVOT FROM A FIRST POSITION OPPOSITE THE STRIPPING DEVICE AND IN WHICH POSITION THE STRIPPING DEVICE STRIPS A WIRE END HELD BY THE JAWS TO A SECOND POSITION IN WHICH THE STRIPPED WIRE END IS LOCATED OVER A CRIMPING FERRULE ON A CRIMPING ANVIL OF THE CRIMPING PRESS SO THAT THE FERRULE CAN BE CRIMPED TO THE WIRE END.

March 16, 1971 c. D. KINDELL ET AL 3,570,100 INSULATION STRIPPING ATTACHMENT FOR ELECTRICAL CONNECTOR CRIMPING PRESS AND CONNECTOR CRIMPING PRESS HAVING INSULATION STRIPPING MEANS 3 Sheets-Sheet 1 Filed May 1, 1969 INVENTOR Colin David Kindell T rence Robert Raynor By m March 16, 1971 c. D. KINDELL ETAL 3,570,100

INSULATION STRIPPING ATTACHMENT FOR ELECTRICAL CONNECTOR CRIMPING PRESS AND CONNECTOR CRIMPING PRESS HAVING INSULATION STRIPPING MEANS Filed May 1, 1969 3 Sheets-Sheet I FIG. 2.

INVENTOR Colin David Kindell A orence Robert Raynor March 16, 1971 Q KmDELL ET AL 3,570,100

INSULATION STRIPPING ATTACHMENT FOR ELECTRICAL CONNECTOR CRIMPING PRESS AND CONNECTOR CRIMPING PRESS HAVING INSULATION STRIPPING MEANS Filed Mayl, 1969 3 Sheets-Sheet 3 5 L- .J,T 290 42 300 i! i' 3 7 as l l 60 l/Vl/EA/TOR Colln David Kindell Terence Robert Raynor United States Patent O 3,570,100 INSULATION STRIPPING ATTACHMENT FOR ELECTRICAL CONNECTOR CRIMPING PRESS AND CONNECTOR CRIMPING PRESS HAV- ING INSULATION STRIPPING MEANS Colin David Kindell, Bushey, and Terence Robert Raynor,

Chingford, London, England, assignors to AMP Incorporated, Harrisburg, Pa.

Filed May 1, 1969, Ser. No. 820,816 Claims priority, application Great Britain, May 3, 1968, 21,012/ 68 Int. Cl. H01r 43/04 US. Cl. Z9203 11 Claims ABSTRACT OF THE DISCLOSURE A stripper attachment for a crimping press comprises wire gripping jaws and an insulation stripping device. The jaws are mounted on a jaw-operating cylinder which swings about a pivot from a first position opposite the stripping device and in which position the stripping device strips a wire end held by the jaws to a second position in which the stripped wire end is located over a crimping ferrule on a crimping anvil of the crimping press so that the ferrule can be crimped to the wire end.

Presses for crimping electrical connectors to wires may or may not be provided with means for stripping the insulation from the end of an insulated wire to which an electrical connector is to be crimped by means of the press. Presses which are not provided with insulationstripping means are used where the insulation need not be stripped from the wire end, that is to say where the connectors are provided with insulation-piercing means, for example lances which pierce the insulation of the wire end to make electrically-conductive contact with the core of the wire, or where the dies of the press are formed to cause the connector to disrupt enamel insulation on the wire so that the connector makes electrically-conductive contact with the wire core.

It is impracticable to use a known press provided with insulation-stripping means, where the wire end is not to be stripped, since the stripping means form an integral part of the press and cannot be readily dismantled from the press or readily immobilized.

According to one aspect of the invention, a wire insulation-stripping attachment for a connector-crimping press comprises a frame for operative attachment to the crimping press, wire-gripping means and an insulation-stripping device each mounted on the frame, the wire-gripping means being mounted for movement between a first position in alignment with insulation-stripping blades of the insulation-stripping device and a second position in alignment with a crimping station of the press when the frame is operatively attached to the press, the stripping blades being arranged to strip the insulation from the end of the electrically-conductive core of an insulated wire when gripped by the wire-gripping means when in its first position and the wire-gripping means when in its second position being arranged to present the stripped end of the core to the crimping station when the frame is operatively attached to the press.

According to another aspect of the invention, a press for crimping an electrical connector to a wire end, comprises a pair of connector-crimping dies relatively movable from an open to a closed position to crimp a substantially U-section ferrule part of an electrical connector to the end of a wire when the ferrule part and wire end are inserted between the dies, a wire insulationstripping device including stripping blades mounted to one side of the dies, wire-gripping means mounted for "ice movement between a first position in alignment with the insulation-stripping blades and a second position in alignment with the space between the dies when in their open position, the insulation-stripping blades being arranged to'strip the insulation from the end of the electricallyconductive core of an insulated wire when gripped by the wire-gripping means when in its first position and the wire-gripping means being arranged when in its second position to present the stripped end of the core between the dies when in their open position to enable the electrical connector to be crimped to the stripped end of the core by closure of the dies.

The wire-gripping means may comprise wire-gripping jaws mounted on a member pivotable to move the wiregripping means between their first and second positions, the member being conveniently formed by a piston-andcylinder unit for moving the jaws between an open and a closed position and being pivotable about an axis extending parallel to the longitudinal axis of the wire end when gripped by the jaws. The wire-gripping means may otherwise be mounted for example for rectilinear movement between their first and second positions. To this end the piston-and cylinder unit may, instead of being pivotably mounted, be mounted on the piston of a second pistonand-cylinder unit.

The jaws preferably have flat surfaces which cooperate to grip the wire end between them. These flat surfaces may have wire-guiding projections extending in the direction of relative movement of the jaws. A wire-guiding projection of one jaw may be slidably received in a slot in the other jaw.

The insulation-stripping device may be of the type disclosed in co-pending British patent application No. 18,783/ 68 in which the stripping blades are closable about the wire end by a movable blade operating member against the action of a first spring, the closure of the blades being limited by a stop so that the blades substantially sever a portion of insulation from the wire end while leaving the electrically-conductive core of the wire unsevered, the blade-operating member being arranged to entrain the blades subsequent to their closure about the wire end to withdraw the blades from the wire end against the action of a second spring which is of greater strength than the first spring, to strip the severed portion of the insulation from the wire end.

The operation of the press may be initiated by an electrical switch, for example a pedal switch, this switch being selectively connectable to a first circuit arranged so that both the insulation-stripping and crimping operations are carried out automatically, upon actuation of the switch or to a second circuit arranged so that only the crimping operation is carried out upon actuation of the switch.

The switch may be arranged to actuate a first fluid valve to cause the wire-gripping means to grip the wire end and subsequently to cause the blade-operating member to close and entrain the insulation-stripping blades and to actuate a second fluid valve to cause the wire-gripping means to be translated from their first to their second position to actuate means for causing the dies to crimp the connector to the stripped end of the core. One of the dies may be arranged upon completion of the crimping operation to actuate a third fluid valve to reset the first and second valves to return the wire-gripping means and the insulation-stripping means to their initial positions, the second valve upon being reset being arranged to cause the third valve to be reset.

The fluid valves may conveniently be comprised in a unitary valve assembly which can be attached to the frame of the press.

An object of the invention is to provide an insulationstripping device for attachment onto a connector-crimping machine which is provided with a first position of operation to strip an end of the insulation from an insulated wire and a second position of operation wherein the stripped end of the wire is placed in alignment with a ferrule of an electrical connector disposed in a crimping station.

Another object is the provision of an insulation-stripping device having pivotal wire-gripping means for gripping the wire to maintain the wire at the first position while the wire is being stripped and then transferring the stripped wire to the second position so that the stripped end of the wire is placed in alignment with the connector ferrule.

A further object is to provide an electro-pneumatic system to automatically operate the stripping and transferring operations of the insulation-stripping device during the crimping operations of the crimping machine.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

For a better understanding of the invention, reference will now be made, by way of example, to the accompanying drawings, in which:

FIG. 1 is a side elevational view of an insulation-stripping attachment comprising an insulation-stripping device, shown partly in section, for a press for crimping electrical connectors to wire;

FIG. 2 is an enlarged elevational view of a detail of an insulation-stripping device;

FIG. 3 is an enlarged elevational view illustrating the operation of the insulation-stripping device;

FIG. 4 is a front elevational view of the attachment when assembled to the press, which is shown in broken lines;

FIG. 5 is an enlarged perspective view of part of a strip of electrical connectors for use with the press; and

FIG. 6 is a diagram of the electro-pneumatic operating circuit of the attachment.

As shown in FIG. 1, the insulation stripping device described in the aforementioned co-pending application comprises a carriage 1 slidably mounted in a housing 2 having brackets 3 secured to a sheet metal frame 100 of the attachment. A lever 4 is pivotally secured between its ends to the carriage 1 by a pivot pin 5. A roller 101 may be pivotally mounted to the right-hand end of lever 4 (as seen in FIG. 1). A first insulation-stripping blade 6 is fixed to the left-hand end of the lever 4 (as seen in FIG. 1) and extends at right-angles to the longitudinal axis of the lever 4 the blade 6 having a V-shaped Wirereceiving notch 7 at its lower end (as seen in FIGS. 2 and 3). A second insulation-stripping blade 8 similar to the blade 6 is attached to the left-hand end (as seen in FIG. 1) of a support plate 9 fixed to the carriage 1. An upstanding-wire stop 10 is fixed to the plate 9 by a fastener 11 the stop 10 being adjustable axially of the plate 9.

A first spring 12 acts between the plate 9 and the lever 4 to urge the lever 4 in a clockwise sense of rotation about the pin 5 (as seen in FIG. 1). A stop screw 13 is threaded through a tapped hole (not shown) in the lever 4 and extends between the lever 4 and the plate 9. Fixedly mounted at the right-hand end of the housing 2 (as seen in FIG. 1) is a cylinder 14 of a pneumatic piston-andcylinder arrangement having a piston rod 15 with a head 16 carrying a cam 17. A second spring 18, which is of greater strength than the spring 12, acts between the carriage 1 and a plate 19 secured to the cylinder 14, to urge the carriagel to the left (as seen in FIG. 1).

The frame 100 comprises a Hat metal plate 20 to which the brackets 3 are secured and a plate 22 secured to and extending perpendicularly to the plane of the plate 20. On the opposite side of the plate 20 to that on which the brackets 3 are mounted, is a clevis 24 (FIG. 4) having pivotally mounted therein a cylinder 26 of a pneumatic pistonand cylinder arrangement having a piston rod 28 carrying a further clevis 30 in which is pivotally mounted an arm 32 fixed to a cylinder 34 of a further piston-and-cylinder arrangement pivotally mounted to the plate 22 by a pivot pin 36. The cylinder 34 has a piston rod 38 carrying a first wire-gripping jaw 40 having a fiat wire engaging surface 41 carrying a first wire-guiding cusp 42. A further wire-gripping jaw 44 fixedly attached to the cylinder 34 by a support 46 has a slot 43 slidably receiving a second wire-guiding cusp of the jaw 40, and has a fiat wire-engaging surface 47.

The plate 22 has at its lower end (as seen in FIGS. 1 and 4) a flange 48 which (as shown in FIG. 4) rests upon the base plate 49 of a press 200 (shown in broken lines) for crimping electrical connectors to wires. The flange 48 is releasably secured to the base plate 49 by bolts (not shown) the plate 20 also being releasably secured by bolts (not shown) to an upright 50 of the press frame.

A tool holder 52 is attached to one end of a press ram 54 which is slidably mounted in the press frame and carries a female crimping die 56 having a connectorcrimping recess 58 providing the working surfaces of the die 56. Beneath the die 56 is an anvil support 60 in which is mounted a crimping anvil 62 forming a malecr'imping die for reception in the recess 58.

The press 200 has means (not shown) for feeding electrical connectors 300 (FIG. 5) arranged in end-toend strip form and each comprising a U-section crimping ferrule 64 and an electrical-connecting portion in the form of a ring tongue 66, towards the anvil 62. The strip of connectors is arranged to be advanced by a feed finger (not shown) a connector length at a time, in a direction perpendicular to the plane of FIG. 4 and towards the reader, to position the crimping ferrule 64 of each connector upon the anvil 62. The feed finger may be operated for example through a linkage (not shown) actuable by the ram 54.

Reference will now be made to FIG. 6. An electric pedal switch 67 is arranged, when actuated, to switch a valve V1 to cause air pressure to be supplied from an air supply main duct M through an unthrottled passageway 68 to the cylinder 34 to cause the piston rod 38 to be advanced against the action of a spring 69 to move the jaw 40 towards the jaw 44 to close these jaws. The actuation of the switch 67 also causes air pressure to be supplied through the valve V1 to a throttled passageway 70 to the cylinder 14 to retract the piston rod 15 which is normally in a fully-advanced position. During the retraction of the piston rod 15, a projection 72 on the piston rod 15 trips a micro-switch 74 to cause air pressure to be supplied from the duct M via a springreturn valve V2 through a throttled passageway 76 to the cylinder 26 to cause the piston rod 28, which is normally in a fully-advanced position, to be fully retracted to cause the cylinder 34 to be gradually rotated in a clockwise sense (as seen in FIG. 4) until the jaws 42 and 44, which are now in their closed position, lie opposite the space between the anvil 62 and the recess 58 of the die 56. When the piston rod 28 has been fully retracted, the cylinder 34 strikes a micro-switch 78 to actuate a solenoid 79 to close contacts 83 to operate a one-shot clutch (not shown), to couple the ram 54 to a continuously running electric motor (not shown) so that the ram 54, which is normally in its top-dead-center position, is driven through a working, i.e. downward stroke (as seen in FIG. 4). When the ram 54 reaches its bottom-dead-center position, a projection 81 of the ram 54 trips a micro-switch 80 to change over a valve V3 to reset the valve V1 to cause the air to be exhausted from the cylinder 34 so that the piston rod 38 is retracted by the spring 69. The changeover of the valve V1 also causes air to be supplied from the duct M to the cylinder 14 via a passageway 91 to cause the piston rod 15 of the cylinder 14 to be advanced. As the piston rod 15 is advanced, the projection 72 releases the switch 74 to cause the valve V2 to be reset by its spring to cause the rod 28 of the cylinder 26 to be advanced. The valve V3 is reset as a result of the resetting of the valve V1. The ram is automatically returned to its top-dead-center position.

The terms throttled and unthrottled are used above in a relative sense, the effective cross-sections of the passage-ways 68, 70 and 76 being adjustable by throttles T. The valves V1 to V3 are preferably provided in a single assembly which can be releasably secured to the press frame or mounted in a box disposed by the side of the press 200.

At the beginning of a cycle of operation, the parts are in their normal positions. The jaws 40 and 44 are thus open, the cylinder 34 is in the angular position in which it is shown in FIG. 4 and the piston rod 15 is fully advanced so that the cam 17 lies between the pin 5 and the spring 12. The lever 4 is accordingly urged by the spring 12 into a fully-clockwise position about the pin 5, so that the blades 6 and 8 are in a fully-open position. An end 400 of an insulated electrical wire having insulation 500 and a central electrically-conductive core 600 is now inserted between the open jaws 40 and 44 (FIG. 4) in the direction indicated by the arrow A in FIG. 1. The wire end 400 is advanced until its extremity, after passing through the V-shaped notch 7 of the blade 6 engages the wire stop 10, a wire guide (not shown) being preferably provided to guide the wire end 400 through the notch 7 and against the wire stop 10. The pedal switch 67 is now pressed so that the piston rod 38 is first advanced to close the jaws 40 and 44 (FIG. 1) about the wire end 400 which is securely gripped between the flat surfaces 41 and 47 of the jaws 40 and 44. The fact that these surfaces are flat, minimizes permanent deformation of the insulation 500. By virtue of the throttling of the passageway 70, the piston rod is retracted with delay, i.e. subsequently to full closure of the jaws 40 and 44 about the wire end, so that the cam 17 is moved from its normal position in which the free end of the cam 17 lies somewhat to the left (as seen in FIG. 1) of the pin 5, to the position in which the cam 17 is shown in FIG. 1. During this move ment of the cam 17, the cam 17 engages the roller 101 mounted on the lever 4 and rotates lever 4 against the action of the spring 12 until the stopscrew 13 engages the plate 9 as shown in FIG. 1. The blades 6 and 8 are thus closed about the wire end 400 so that the edges of the V- shaped notches of the blades 6 and 8 substantially sever a portion 700 of the insulation 500 from the wire end as best seen in FIG. 3. As the retraction, i.e. working stroke of the piston rod 15 continues, the carriage 1 is pulled towards the plate 19 by the cam 17 since the lever 4 is locked against further rotational movement as a result of the engagement of the screw 13 against the plate 9. The blades 6 and 8 are accordingly moved axially away from the wire end 400, which is retained against movement relative to the frame 2 by the jaws 40 and 44, to drag the severed portion 700 of insulation from the end of the core 600. The piston rod 28 is now retracted as a result of the retraction of the piston rod 15 so that the cylinder 34 and thus the jaws 40 and 44, which are closed about the wire end 400 which has now been stripped, are moved to their fully clockwise angular position. The distance between the jaws 40 and 44 and the stop 10 in the initial position of the parts, is such that in the fully clockwise position of the cylinder 34 the stripped end of the wire end 400 lies slightly above the crimping ferrule 64 of a connector 300 on the anvil 62, this connector having been advanced onto the anvil 62 by the feed finger during the previous return stroke of the ram 51. As a result of the cylinder 34 reaching its fully clockwise position, the ram 54 descends, i.e. carries out a working stroke, to crimp the ferrule 64 of the connector 300 on the anvil 62 to the stripped end of the core 600 which is guided into the ferrule 64 by the walls of the recess 58. As the ram carries out its return stroke, the jaws 40 and 44 are opened so that the wire end with the connector 300 crimped thereto can be removed from between the die 56 and anvil 62, the piston rod 15 being returned to its fully-advanced position and the cylinder 34 returned to its fully anti-clockwise angular position.

The jaws 40 and 44 may be arranged to be opened after the cylinder 34 has been returned to its fully anticlockwise angular position. If, however, as may sometimes be the case, the connector 300 is such that its ferrule 64 sticks in the recess 58 of the crimping die after the crimping operation, the jaws 40 and 44 should be arranged to open as soon as the ram 54 begins its return stroke.

If the insu1ation-stripping attachment is not to be used, the pedal switch 67 may be disconnected from the valve V1 and reconnected to terminals 92 of the solenoid 79 so that the solenoid 79 is operated when the pedal switch 67 is actuated to cause the ram 54 to be driven through its working and return strokes. The valves V1 to V3 and their associated electro-pneumatic elements are in this case out of circuit.

It will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it should be emphasized that the particular embodiment of the invention, which is shown and described herein, is intended as merely illustrative and not as restrictive of the invention.

The invention is claimed in accordance with the following:

1. A wire insulation-stripping attachment for a connector crimping press comprising a frame for operative attachment to the crimping press, wire-gripping means and an insulation-stripping device each mounted on the frame, insulation-stripping blades provided on said insulation stripping device, means mounting the wire-gripping means for movement between a first position in alignment with said insulation-stripping blades and a second position in alignment with a crimping station of the press, means for moving said wire-gripping means into engagement with an insulated wire, means for operating said insulationstripping blades to strip the insulation from the end of the electrically-conductive core of the insulated wire when gripped by the wire-gripping means when in its first position, and means for arranging the wire-gripping means to its second position to present the stripped end of the core to the crimping station.

2. An attachment as claimed in claim 1, in which the wire-gripping means include wire-gripping jaws mounted on a member pivotable between the first and second positions.

3. An attachment as claimed in claim 2, in which the member is a piston and cylinder arrangement for moving the jaws between an open and a closed position, the piston and cylinder arrangement being pivotable about an axis extending parallel to the longitudinal axis of the wire end when the wire is gripped 'by the jaws.

4. An attachment as claimed in claim 2 in which the wire-gripping jaws have fiat surfaces which co-operate to grip the wire between them.

5. An attachment as claimed in claim 4, in which the flat surfaces are provided with wire-guiding means extending in the direction of relative movement of the jaws.

6. An attachment as claimed in claim 5, in which the wire-guiding means include a projection on one jaw which is slidably received in a slot in the opposite jaw.

7. An attachment as claimed in claim 1 in which the insulation-stripping blades are closable about the wire end against the action of a first spring by a movable blade-operating member, the closure of the blades being limited by a stop so that the blades substantially sever a portion of the insulation from the wire end while leaving the electrically-conductive core of the wire unsevered.

8. An attachment as claimed in claim 7 in which the blade-operating member is arranged to entrain the blades subsequent to their closure about the wire end to withdraw the blades from the wire end against the action of a second spring, which is of greater strength than the first spring, to strip the severed portion of the insulation from the wire end.

9. An attachment as claimed in claim 8 in which the blades are mounted on a carriage which is slidable in a housing against the action of the second spring, at least one of the blades being carried by a lever pivotably mounted in the carriage and engageable by the bladeoperating member to open and close the blades.

10. An attachment as claimed in claim 9 in which the blade-operating member is a cam movable between the lever and a guide surface of the carriage along a path extendnig transversely of the pivotal axis of the lever, the cam permitting the lever to swing in one sense under the action of the first spring to open the blades when the cam is disposed on one side of the pivotal axis of the lever, the cam causing the lever to swing in the opposite sense against the action of the first spring to close the blades when the cam is moved to the opposite side of the pivotal axis.

11. A press for crimping an electrical connector to a wire end comprising a pair of connector-crimping dies relatively movable from an open to a closed position to crimp a ferrule part of an electrical connector to the end of a wire when the ferrule part and wire end are inserted between the dies, a wire insulation-stripping device including stripping blades mounted to one side of the dies, wire-gripping means mounted for movement between a first position in alignment with the insulationstripping blades and a second position in alignment with the space between the dies when in their open position, means for operating the insulation-stripping blades to strip the insulation from the end of the electrically-conductive core of an insulated wire when gripped by the wire-gripping means when in its first position, and means for arranging the wire-gripping means when in its second position to present the stripped end of the core between the dies when in their open position to enable the electrical connector to be crimped to the stripped end of the core by closure of the dies.

References Cited UNITED STATES PATENTS 4/1968 Sitz 29203 11/1969 Van de Kerkhof 29203 

